Method for manufacturing photomask and semiconductor manufacturing method thereof

1. A semiconductor manufacturing method, comprising: providing a first layout including a plurality of first features and a second layout including a plurality of second features, wherein at least one of the second features partially overlaps at least one of the first features, and the first layout and the second layout are at different levels; shifting the second layout to generate a plurality of virtual layouts from the second layout, wherein each of the plurality of virtual layouts includes a plurality of shifted second features; calculating a score for each of the plurality of virtual layouts in accordance with a total overlay area between the plurality of first features and the plurality of shifted second features; comparing the score of each of the plurality of virtual layouts and determining a modified second layout having a target score out of the plurality of virtual layouts; and outputting the modified second layout to a photomask.

2. The semiconductor manufacturing method of claim 1 , the target score is the greatest score out of the scores of the plurality of virtual layouts.

3. The semiconductor manufacturing method of claim 1 , wherein the score of the virtual layout is calculated based on the total overlay area and relative positions of the plurality of first features and the plurality of shifted second features.

4. The semiconductor manufacturing method of claim 3 , wherein the relative positions are determined by calculating a distance between a center of each of the plurality of first features and a center of each of the plurality of shifted second features.

5. The semiconductor manufacturing method of claim 1 , wherein the plurality of first features and the plurality of the shifted second features are disposed sequentially in a semiconductor.

6. The semiconductor manufacturing method of claim 1 , prior to providing the first layout, further comprising: providing an original first layout comprising a plurality of original first features; and shifting the plurality of original first features to provide the first layout.

7. The semiconductor manufacturing method of claim 1 , wherein the plurality of first features of the first layout and the plurality of second features of the second layout represents a common area of two layers at different levels of elevation in a semiconductor device.

8. A semiconductor manufacturing method, comprising: providing a first layout of a metal layer to be disposed in a semiconductor device; generating a second layout of a via layer to be disposed in the semiconductor device over the metal layer, the second layout overlapping the first layout from a top view perspective; calculating a score in accordance with an offset between the first layout and the second layout; subtracting a predetermined value from the score to generate a delta; shifting the second layout of the via layer to reduce the delta if the delta exceeds a threshold value.

9. The semiconductor manufacturing method of claim 8 , wherein the offset is determined by a total overlay area of the first layout and the second layout from a top view perspective.

10. The semiconductor manufacturing method of claim 8 , wherein the offset is determined by a total overlay area and a distance between a center of the first layout and a center of the second layout.

11. The semiconductor manufacturing method of claim 8 , wherein the via layer is sequentially formed over the metal layer for electrical connection with the metal layer of the semiconductor device.

12. The semiconductor manufacturing method of claim 8 , wherein a feature of the via layer is outside of a coverage area of the metal layer prior to shifting the second layout of the via layer.

13. The semiconductor manufacturing method of claim 1 , wherein the plurality of virtual layout and the second layout are substantially at a same level.

14. A method for manufacturing a semiconductor device, comprising: providing a first layout including a plurality of first features and a second layout including a plurality of second features; shifting the second layout to generate a modified layout from the second layout, wherein the modified layout includes a plurality of shifted second features overlapping the first layout from a top view perspective; outputting the first layout to a first photomask and forming a metal layer of a semiconductor device through the first photomask; and outputting the modified second layout to a second photomask and forming a via layer over the metal layer of the semiconductor device through the second photomask.

15. The method of claim 14 , wherein the first layout and the second layout are formed in an interconnect structure of the semiconductor device at different levels of elevation.

16. The method of claim 14 , wherein each of the plurality of shifted second features at least partially overlaps each of the plurality of first features.

17. The method of claim 14 , wherein the modified layout is generated by shifting at least one of the second features of the second layout.

18. The method of claim 14 , wherein the plurality of shifted second features in the modified layout is shifted according to a plurality of shift values relating to the plurality of second features of the second layout.

19. The method of claim 14 , wherein the via layer is electrically connected to the metal layer.

20. The method of claim 14 , wherein the first layout is generated from a design layout after an optical proximity correction (OPC) operation.